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- Title
Effects of different alkalis on the behaviour of vanadium loss in the pretreatment of vanadium-bearing acid leaching solution.
- Authors
Qiaoqiao Zheng; Yimin Zhang; Shenxu Bao; Jing Huang; Guobin Zhang
- Abstract
This study examined the effect of different pretreating agents on vanadium loss from vanadium-bearing shale. Acid leaching solutions with added Ca(OH)2, CaCO3, NaOH, Na2CO3, and ammonia solution were evaluated. The pH of the acid leaching solution was adjusted to 2.0 to reduce vanadium loss and allow efficient r emoval of impurities, providing a high vanadium extraction efficiency. Ca(OH)2 was the most effective neutralizer and its use resulted in a vanadium loss rate of as low as 4%. SEM-EDS analysis indicates that a major cause of vanadium loss is entrapment and absorption by precipitates. The low vanadium loss rate using Ca(OH)2 as a neutralizer appears to be due to the smooth and flat surface of the precipitate, which limits vanadium entrainment. When the pH was adjusted with CaCO3, the crystal structure of the precipitate was incomplete. In addition, CaSO4 and iron phosphate particles interact, promoting entrainment and absorption of vanadium. Similarly, flocculent iron phosphate was generated when the pH was adjusted with NaOH, Na2CO3, or ammonia, resulting in a crystal with a rough surface that easily entrained vanadium.
- Subjects
VANADIUM; ACID solutions; AMMONIA; ALKALIES; CRYSTAL surfaces; ROUGH surfaces; CRYSTAL structure
- Publication
ScienceAsia, 2019, Vol 45, Issue 1, p43
- ISSN
1513-1874
- Publication type
Article
- DOI
10.2306/scienceasia1513-1874.2019.45.043